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Any problems with 4.88 gears

7

77 Mud Buddy

1/2 ton status
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I just posted about my gears but I now have another question.

I have heard rumor that 4.88 gears are a gamble because the pinion gear starts to get so small that it is suseptable to breakage. Has anybody had problems with the pinion gear on 4.88's or higher. I guess mainly I am asking for my D44 front, I am not expecting my, Soon to be installed, 14 bolt to have a problem with them.
 
Some people question the pinion strength of the 4.88's and up. I used to. I saw a pick of one and it seemed pretty decent sized. I have testimonials from 4.88 and up owner who haven't had a problem.

People have told me to worry more about the shrinking tooth to tooth contact area on the R&P more then the pinion strength.

I personally am going to run 4.88's or 5.13's in my next trail only truck. It is going to be pretty light as K5's go though.
 
4.89 may well be stronger than the 4.56 since it has 9 pinion teeth instead of 8.
 
COOL, I figured gear companys wouldnt sell em if they wouldnt work well. I feel better about my 4.88 purchase now, Thanks for the info.
 
Actually these are valid points. The lower a gear ratio is (numerically higher) the less tooth contact area and the weaker the pinion is. 4.88's supposedly get into the weak area for the half ton axles with 8.5" ring gears. Guys who run 5.13's and such are almost always running Dana 60's and 14BFF, which have much larger gears so they can get away with it. WIth half ton stuff I'd stick to 4.56's for that reason.
 
im running 4.88s in my 1/2 ton 10 bolts and i havent had a problem yet. and even if they break i have an unlimited lifetime warrenty so its ok /forums/images/graemlins/thumb.gif
 
I agree with your points on that Zakk, if I had a 700R4 I'd get the 5.13's. But as it is I'm looking to some 35-37" tires to drop my rpm on the road... 4:10's + 33's + no OD + 454 = crappy highway trips. I think the motor won't have a problem pulling the larger tires, the only thing I question is how the driveshafts will like it...

Ultimately, I plan on having 5.13's with some sort of overdrive setup, just to lessen the strain on the driveshafts. It'll probably wear out u-joints just as fast due to the higher rpm the shafts are turning, but thats better than physically breaking them or twisting a shaft. It's also easier on motor and tranny mounts/adapters.
 
well. to be frank (actually, i'm zakk and your Justin, but that is besides the point, or maybe in front of, oh well.) 1-ton with 33" tires and your hanging that 14BFF on speed bumps unless you went "vova" on it and made it a 13BFF.

with added meats 38+ (which I presume is the reason you went 1-ton) that wouldn't be all that bad.
 
I agree with your statement for the most part. I personally am only running 4.56's because I (at the time) thought that this would be a little to deep gear wise for me. Now I know I was wrong in my analysis. The only thing I have problems with is this:

(I run 4.56's and 32's (31") which is like 5.13's and 37's)

The cruise in OD is great. Perfect RPM for most SBC's. But when you are on a mountain grade and have to shift back to D you are spinning alot of RPM's. (I personally spin 3200+ rpm on mountain grades. I have spun upward of 3500 to roughly 3800-4000rpm before climbing hills) The power is great because I can pass on 6-7% grades, but it is to many RPM for my personal liking if you are running a long hill.
 
I agree with that 14 bolt statement. I run the 32's on a 14bff (have a set of 35's for offroad now). I have turned mine into a 13 1/2 bolt full floater, and I still hang in on anything resembling a rock.

The first time out I cruising in a creek bed and drug it on a rock that I didn't even take into account since I was used to the 10 bolt rear.

Second time out I hung it on a rock that was pretty tame by anybody's standard. But the 35's are hear now and hopefully some 37-38's are on the way.
 
[ QUOTE ]
I agree with your points on that Zakk, if I had a 700R4 I'd get the 5.13's. But as it is I'm looking to some 35-37" tires to drop my rpm on the road... 4:10's + 33's + no OD + 454 = crappy highway trips. I think the motor won't have a problem pulling the larger tires, the only thing I question is how the driveshafts will like it...

Ultimately, I plan on having 5.13's with some sort of overdrive setup, just to lessen the strain on the driveshafts. It'll probably wear out u-joints just as fast due to the higher rpm the shafts are turning, but thats better than physically breaking them or twisting a shaft. It's also easier on motor and tranny mounts/adapters.

[/ QUOTE ]im runnin 4.10's tci 350 turbo w/shift kit and no over drive 31's and a 350 and i go threw u joints pretty damn fast
 
That sounds like a driveshaft and or angle problem to me. I have been running the 4.56's and 32's for 9 months, and I am yet to go threw 1 set of joints in the driveshaft. I run my truck in D around town too.
 
[ QUOTE ]
1-ton with 33" tires and your hanging that 14BFF on speed bumps unless you went "vova" on it and made it a 13BFF.

with added meats 38+ (which I presume is the reason you went 1-ton) that wouldn't be all that bad.

[/ QUOTE ]

Ahh yes, 'tis true. The 33's were a leftover from another time, but were in great shape so I used them. Me being a poor fulltime college student I'm not going to toss new 33's so I can spend $1300 on some new swampers for my daily driver....I'm sure you understand. This summer is going to hold some new additions to my ride, and tires is definetly one of them. I'd like to stick to radials because it is my daily driver and I do a lot of sand wheeling, but any 38" radial for a 16 rim is quite pricy. Right now its a toss up between the new 36 14.50R16 TSLR's and getting some 15" steelies and 37" MTR's. My next set (when I get another DD in a year or so) is 95% chance going to be some 42's.
 
I had a 12 Bolt ring gear failure due to improper backlash setting. This was coupled with the fact that only 2-3 teeth on the pinion contact the ring gear under load which puts more stress in the ring gear. I would say my gear failure was due to improper setup.

I have wheeled with Steve from Missouri Offroad Outfitters who has 4.88 gears in 1/2 ton drivetrain and have never seen a problem with his.
 
[ QUOTE ]
That sounds like a driveshaft and or angle problem to me. I have been running the 4.56's and 32's for 9 months, and I am yet to go threw 1 set of joints in the driveshaft. I run my truck in D around town too.

[/ QUOTE ]
thats what i thought 2 but its the shift kit and that tci transmision i am running the stock or regular u joints arnt made to hold up to it or someshit thats what several places have told me but i dont know and o well there only what 8 bucks for a ujoint
 
If you are running 1310 ujoints (stock) then you could have a driveshaft made with 1330, 1350, or 1410 ujoints and you would probably cure your problem. You would need to have your driveshaft rebuilt with the proper ends and also you will need a new yoke.

The larger ujoints are able to withstand higher operating angles.
 
Sounds like its time to go to the drive-shaft shop. Check for bends, dents, and balance. Also buy some Spicer or neapco BF joints.
 
since im basicly restoring it now and i never drive it much im not gonna worry about it now since i have to get a new drive shaft and im getting axles any way so ill do it then /forums/images/graemlins/k5.gif
 
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